I am using the built in sound card on my mobo. That is probably the problem but before I go buy a real sound card I just wanted to ask. I am just using a stereo to mini adapter cable going from my HTPC straight to my Plasma for sound. I don't want surround sound, just want to use the speakers on my Plasma. If I get a sound card will this make the sound louder when watching a movie? And yes I have the sound all the way up on my PC.